Alcohol-reaction catalysts



(See Brun, "Uber den B p r 2,360,394 ."U ITED STATES PATENT OFFICE.

2,300,394 anconon-nmo'rron CATALYSTS Barry Barrel], Paramus, N. 21.,

asslgnor, by nies ne assignments, to Heyden Chemical Corporation, New York, 18.1., a corporation of Delaware m. Drawing.

Application March 9, 1942, Serial No. 433,942 a 19 Claims. (u-2co 41o.c)

This application is a continuation in part of my copending application Serial No. 382,586, filed March 10,1941. 1

It is an object' of this invention to promote the reactions of alcohols including such reactions as alcoholysis, 'esteriflcation and etheriflcation. There is afurther object to aid the reaction of polyhy'dric alcohols, especially pentaerythritol and. polypentaerythritols, and other polyhydric primary alcohols.

In the manufacture of pentaerythritol by the condensation of acetaldehyde and formaldehyde, inaddition to the pentaerythritol itself, smaller amounts of hydroxylated substances are also obtained. One of these obtained in a considerable reaction temperature. Under such conditions th ,4 reaction temperatures ordinarily must be higher amount is dipentaerythritol, which is an ether of the following structure:

' 'omon onion nomc--dnk-m-om-rL-bmon HsOH I l, Wilhelm Greven, Krefeld, 1930.) An ther hydroxylated substance, obtained in somewhat smaller amounts, is white and crystalline, melts at 230- I 240 C. and hasja hydroxyl content of 33%. The chemical structure of this substance is not known,

and there is a possibility that it may be a mixture of chemical entities. It seems fairly certain, however, that it is related to dipentaerythritol in that it contains pentaerythritol residues bound by ether linkages. ture, for purposes Regardless of chemical strucof definition in this specification and in the claims, this substance will be termed pleopentaerythritol. The term is not intended to indicate that the substance is formed either actually or theoretically by combination of 'disadvantages in economy,

and the reaction times longer with the resulting discoloration, losses oi yield, etc. By using certain catalysts as hereinafter; described, such difliculties are minimized. By means of..my invention it is possible to promote the replacementof part of the alcohol residues in esters by pentaerythrityl or polypentaerythrityl groups. It is further possible to promote the alcoholysis of naturally occurring esters such as fatty acid glycerides. It is also possible to prepare hydroxylated partial esters any particular number of pentaerythritol residues,

but merely signifies that it is probably a product similar to pentaerythritol and dipentaerythritol. Dipentaerythritol and pleopentaerythritol may be polypentaerythritolsfi By polypentaerythritols I mean those compoundsof higher molecular weight than pentaerythritol which are formed either actually or theoretically by etherifying one or more of the hydroxyl groups .of pentaerythriotol with a polyhydric alcohol. These polypentaerythritols therefore have either the same number of hydroxyl groups as pentaerythritol (as for instance when an ether is formed between pentaerythritol and a glycol or with pentaerythritol and ethylene oxide); or the polypentaery'thritols may have a greater number of hydroxyl groups than ,pentaerythritol, that is to say five or more (as for instance when an ether is formed between grouped together under the generic term r 'suitablefor further reactions, for example, with dibasic acids for the preparation of alkyd resins -or for further reaction with monobasic acids such as fatty acids in order to prepare fatty oils, especially the drying oils. Furthermore, the esteriflcation of such hydroxylated partial esters and also of the original unesterifled-alcohols is also promoted by the catalysts. It is convenient, for example, in the preparation of alkyd resins, to add the catalyst actions and to allow the catalyst to remain in the reaction mixture so that alcholysis and-esteriflcation are successively or simultaneously pro moted.

It is known that oxides and hydroxides as well as some alcoholates of alkali metals and the alkaline earth metals will promote alccholysis. Lead oxide or litharge has also been frequently used. These substances are not satisfactory for many uses. The alkali metal oxides form soaps which are deleterious to the weathering properties and to the clarity of alkyd resins and drying oils prepared with their aid. The alkaline earth metal oxides cause excessive foaming during the alcoholysis reaction and are frequently too insoluble to be eifective. Litharge promotes the formation of color bodies and in the amounts required for alcoholysis causes an undesirable siccative action This is especially true in the case of pentaerythritol esters of drying oil acids where the use of lead oxide leads to the formation of brittle films and also causes excessive darkening of the pentaerythritol drying oils, thereby limitat the start of a series of re-,

to be active are erally produce highly discolored products, especially with pentaerythritol typ alcohols. The, element of group I which was found to be active was lithium. The preferred elements, therefore,

are lithium and those of group tion of beryllium, magnesium and mercury (the status of radium is not known) namely: calcium, strontium, barium, zinc and.cadmium.

The method of using these metallic salts as alcoholysis catalysts is described in the copending application, 382,586, and also in the following examples. In general, 1 or 2% of the catalysts may be added to the reaction mixture and the reaction carried out in the usual fashion with due regard for the increased reactivity of the system. As esterification catalysts they may simply be added to the esterifying ingredients again with proper concern for the increased speed of reaction.

The following examples are given for illustrative purposes only and should not be construed so as to limit the invention as to proportion and scope.

Example 1.-The following table illustrates the variety of salts suitable for use as alcoholysis catalysts. The procedure for utilizing each of the substances listed was as follows: 200 parts by weight of alkali refined soy bean oil and the catalysts amounting to 1% of the weight of oil were heated with 48 parts of technical pentaerythritol at 230 C. Alcoholysis was considered complete when the pentaerythritol had completely dissolved. If the pentaerythritol did not dissolve after heating for three hours at 230 C., the metallic salt was considered inactive as a catalyst.

Table I Example 2.-To illustrate the general applicability of the catalysts as alcoholysis promoters, soy bean oil was heated with 1% of calcium naphthenate and 25% of the alcohols listed in Table II, at 230 C.

Table II Tuilmelre- 1 e Alcohol used eflect 81W hol Minutes Glycerol. 60 Trimethylol propane. M 'letraethylene glyeoL- 2 Ethylene glycol 1 Butanol Dipentaerythritol l3 Pentaerythritol 5 Pleopentaerythritol. 50

l .Ihe butanol mixture was heated under reflux for 6 hrs. during which time the temperature rose from 124 to 134 C. The excess butanol was then distilled of! and 26% was lead and cerium, but these gen- Example 3.-As an illustration of other esters besides those naturally occurring in soy bean oil, to which the invention may be applied, Table 111 lists the time required to alcoholize the noted ester by the alcohol indicated when 1% calcium naphthenate was added to the ester and the reaction mixture heated at 230 C.

Table III Ester used Alcohol used 3 l Mimuu Coi'itgn seed oil (glycer- Pentaerythritol, technical... I

e Tung oil (glyceride) do I Linseed oil (gly rlde) Pentaerythritol, pure 8 Pentizegrt'ythritol tetra- Pentaerythrltol, technical... l4

ace e. Pentaerythrltol (tech- Glyeerol I nical) tetrastearate,

found to have reacted. (5

Example 4.-l50 parts alkali-refined soy bean oil, 3 parts calcium naphthenate, and 37.5 parts technical pentaerythritol were heated together inan apparatus fitted for stirring the reactants under an inert atmosphere. The ingredients were heated from room temperature up to 250 C. in 31 minutes, at which time the pentaerythritol had substantially completely reacted. The reaction product was immediately cooled to 128 C.

when '73 parts of phthalic anhydride were added,

and the mixture was further reacted at 250 C. for 3.75 hours. The product was an alkyd resin which had a Gardner color of '1 when dissolved in an equal weight of toluol.

Example 5.-150 parts of alkali-refined so! bean oil and 37.5 parts technical pentaerythritol were heated in the nate to 280 C. at which temperature the pentaerythritol had not yet reacted. Some of the pentaerythritol had sublimed on the upper walls of the reaction vessel, some had melted and formed a liquid layer at the bottom, and a small amount had dispersed to form a cloudy suspension in the hot oil. It was necessary to continue heating at 2'l5-280 orous agitation before the pentaerythritol had reacted.

This product was also made into an alkyd resin following the same procedure as in Example 4 and the resultant resin had a Gardner color of 0 when dissolved in an equal weight of toluol.

Example 6.-150 parts alkali-refined soy bean oil, 37.5 parts technical pentaerythritol and 0.38 part litharge were heated under an inert atmosphere to 250 C. in 36 minutes. At this point the pentaerythritol had reacted but the resulting alcoholized soy bean oil was extremely dark colored. The product was cooled and reacted with phthalic anhydride as in Example 4. The resultant alkyd resin hada Gardner color of 11 when dissolved in an equal weight of tomol.

Example 7.-150 parts of alkali-refined soy bean oil, 15 parts purified dipentaerythritol, 3.0 parts calcium naphthenate and 32 parts high flash petroleum naphtha were heated under reflux to 246 C. in 39 minutes. The temperature was then lowered to 92 C. and 100 parts of linseed oil fatty acids were added. The reaction mixture was further heated at 260 C.' for 2 hours allowing the high flash naphtha to distill oil and carry with it by azeotropic distillation the water which was separated in a trap and drawn oil while the high flesh naphtha was returned to the reaction mixture. when substantially the theoretical amount of water had distilled oil, the temperature of the reaction mixture was raised to absence of calcium naphthe- C. for 31 minutes with vigter additions 310- c. to distill oil the high flash sights... The product was a light brown viscous oil consisting of mixed soy bean oil fatty acid. and linseed oil vesso No. 1." The purpose or the petroleum distillate was to azeotropically remove-water of esteriiication. In one case these ingredients were heated under reflux at-200 C. without any i'ur'e and in the other case 12 parts by weight or calcium naphthenate were added to the reaction mixture. The table shows the change in acid numberwith time at 200 C.

Table IV a :1 Acid e 1";-

ea ng numr ime, her, no clun utes catalyst naphthenate added 22 821 can 42 66. 68. 2 62 56. 8 49. 7 B2 62. l 44. 1 103 46. 7 38. 4 121 27.8 181 35.8

The reactions were 01' the second order and the equation for reaction rate may be placed in the form,

. a-b tbwhere K is the reaction constant, a is the initial acid number, b is the acid number after time t.

, ascents group consisting of of lithium, cadmium.

'- esteriilcation 01 a mixture of pentaerythritol and Using this equation, K for the esteriilcation reaction without a catalyst is 0.0099 while K for the esterification with the 1% calcium naphthenate is 0.0225. It may thus be seen that the use of calcium naphthenate as a catalyst increases the reaction rate 2.27 times. I

It may readily -be seen {mm the examples that the ester-soluble salts of lithium, calcium, strontium, barium, zinc, and cadmium are powerful promoters for reactions of alcohols, particularly primary alcohols. the reactions utilizing pentaerythritol-type alcohols. because the high melting point and general. insolubility militates against satisi'actoryreaction rates.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. The process of promoting alcoholysis with pentaerythritol which includes effecting the re- This is especiallyvaluable in ,4. The process "whichincludes promoting the eaterincation oi po ypentaerythritols in the pres ence of an eaten-soluble salt of a metal selected from the group consisting oi lithium, calcium,

strontiumbarium, zinc, and cadmium.

5. The process of alcoholizing an ester with an alcohol which includes heating them in the presence of an ester-soluble salt of a metal selectd trom the group consisting of lithium,-. calcium,

strontium, barium, zinc, and cadmium.

6. The process oi alcoholizing a fatty acid ester oi glycerol with an alcohol selected from the pentaerythritol, polypentacrythritols and mixtures thereof, which includes heating-them. in the salt of a metal selected'i'rom 7. The process which includes promoting the esteriflcation of alcohols which includes eflecting said esteriiication in the presence of an estersoluble salt of a metal selected from the group consisting oi lithium, calcium, strontium, barium, zinc, and cadmium.

8. Theproce ss which includes promoting alcoholysis with a mixture of pentaerythritol and a polypentaerythritol by an ester-soluble salt of a metal selected from the group consisting of lithium, calcium, strontium, barium, zinc, and.

cadmium.

9. The process which includes promoting the a polypentaerythritol by an ester-soluble salt of .a metal selected from the group consisting of lithium, calcium, strontium, barium, zinc, and cadmium..

I 10. The process which includes alcoholizing a fatty acid ester of glycerol with a mixture of pentaerythritol and a polypentaerythritol in the presence of an ester-soluble salt of a metal selected from the group consisting .of lithium, calcium, strontium, barium, zinc, and cadmium.

11. The process which includes heating together a fatty acid ester of glycerol with a mixture of pentaerythritol and a polypentaerythritol in the presence of an ester-soluble salt of a metal selected from the group consisting of lithium, cal- .cium, strontium, barium, zinc, and cadmium.

l2. The process of alcoholizing an ester which includes promoting the alcoholysis by an estersoluble salt of a metal selected from ,the group consisting of lithium, calcium, strontium, barium,

zinc, and cadmium.

13. The process of alcoholizing a fatty acid ester of glycerol with an alcohol selected from the group consisting of pentaerythritol, polypentaerythritols and mixtures thereof, which consists in reacting them in the presence of zinc naphthenate as a catalyst.

14. The process of alcoholizing an ester which includes promoting the alcoholysis by an esteraction in the presence of an ester-soluble. salt oi a metal selected from the group consisting of lithium, calcium, strontium, barium, zinc, and

cadmium.

2. The process which includes promoting alcoholysis with polypentaerythritols by the action of an ester-soluble salt of a lnetalselected from soluble stearate of a metal selected from the group consisting of lithium, calcium, strontium, barium, zinc, and cadmium.

15. The process of alcoholizing an ester which includes promoting the alcoholysis by an estersoluble resinate of a metal selected from the group consisting of lithium, calcium, strontium,

. barium, zinc, and cadmium.

16. The process of alcoholizing an ester which includes promoting the alcoholysis by an estersoluble naphthenate of a metal selected from the group consisting of lithium, calcium, strontium, barium, zinc, and cadmium;

17. The process of alcoholizing soybean oil presence oi amester-solublethe group consisting calcium..strontium, barium, zinc, and

with an alcohol selected from the group consisting of pentaerythritol, polypentaerythritol and mixtures thereof, which includes reacting them in the presence of an oil soluble salt of lithium, calcium, strontium, barium, zinc, and cadmium.

'18. The process of alcoholizing linseed oil with an alcohol selected from the group consisting of pentaerythritol, polypentaerythritol and mixtures thereof, which includes reacting them in the presence of an oil soluble salt of lithium, calcium, strontium, barium, zinc, and cadmium. r h 19. The process of alcoholizinz linseed oil with pentaerythritol, which includes reacting them in the presence of a. resinate o! a metal selected from the group consistingo! lithium, calcium,

strontium, barium, zinc and cadmium.

HARRY BURRHJ-I. 

